Machine for cutting slabs from ice blocks

ABSTRACT

A rotatable table carries a plurality of open-bottomed holders for blocks of material to be cut, more specifically dry ice. Under the table is a sector plate of about 240* to 270* of arc and spaced from the bottom surface of the table by a vertical distance not greater than the smallest thickness of slab to be cut. Beyond one edge of the sector plate, is mounted an indexing platform the height of which can be adjusted according to the exact thickness of slab desired. Beyond the edge of the indexing plate and still within the open portion of the sector plate, is a horizontal bandsaw blade operable with a slight clearance space from the bottom of the table. The block to be cut slides upon the sector plate as the table rotates and drops onto the indexing platform. Means then are actuated to hold the block in suspension within the holder as the block approaches the saw blade. An even cut is made parallel to the bottom face of the block without danger of jamming or breaking the block. When the clamped upper portion of the block is carried over the sector plate again, the clamping means is released and the block falls to the sector plate in preparation for another cut. A chute is provided below the saw blade and a sweeper arm is actuated after every cut to remove any debris from the indexing platform.

ilnited States Patent Michals et a1.

[54] MACHINE FOR CUTTING SLABS FROM ICE BLOCKS [72] Inventors: ChesterS. Michals, North Hyde Park,

N.Y.; Philip J. Motroni, Fox Lake, 111.

[73] Assignee: Air Reduction Company, incorporated,

New York, N.Y.

[22] Filed: Oct. 1, 1968 [21] Appl. No.: 764,134

[ Feb.8,1l9'72 Primary Examiner-Andrew R. .Iuhasz AssistantExaminer-Leon Gilden Attorney-Francis B. Henry, Edmund W. Bopp and H.Hume Mathews [57] ABSTRACT A rotatable table carries a plurality ofopen-bottomed holders for blocks of material to be cut, morespecifically dry ice. Under the table is a sector plate of about 240 to270 of arc and spaced from the bottom surface of the table by a verticaldistance not greater than the smallest thickness of slab to he cut.Beyond one edge of the sector plate, is mounted an indexing platform theheight of which can be adjusted according to the exact thickness of slabdesired. Beyond the edge of the indexing plate and still within the openportion of the sector plate, is a horizontal bandsaw blade operable witha slight clearance space from the bottom of the table. The block to becut slides upon the sector plate as the table rotates and drops onto theindexing platform. Means then are actuated to hold the block insuspension within the holder as the block approaches the saw blade. Aneven cut is made parallel to the bottom face of the block without dangerof jamming or breaking the block. When the clamped upper portion of theblock is carried over the sector plate again, the clamping means isreleased and the block falls to the sector plate in preparation foranother cut. A chute is provided below the saw blade and a sweeper armis actuated after every cut to remove any debris from the indexingplatform.

5 Claims, 6 Drawing Figures WENTEDFEB 8H7? SHEET 1 [IF 2 F/GZ INVENTORSPHlLIP J. MOTRONI CHESTER s. MICHALS BY 8% ATTO RN EY MACHINE FORCUTTING SLABS FROM ICE BLOCKS FIELD OF THE INVENTION The inventionrelates to a semiautomatic device particularly for preparing slabs ofsolid carbon dioxide (dry ice), although the device can be used to cutother solid materials. The slabs are especially for use in airline foodcontainers which transported to the aircraft and while the aircraft isairborne.

The dry ice blocks are clean, contain high refrigerant capaci ty,sublime slowly and leave no residue. Thus there is no cleanup problemfor stewardesses, etc. Furthermore, there is no need for a mechanicalrefrigerating system on the aircraft to keep food cool.

DESCRIPTION OF THE PRIOR ART While the above-described use fordry iceslabs is well known, there has heretofore been no really economical wayto produce slabs of this size in quantities sufficient to supply largeairfields.

In the past, the large solid dry ice blocks by 10 by 10 inches) were cutmanually using bandsaw, into slabs which were 5 by 5 by 1 inches forsale to the airlines. This procedure has proven extremely burdensome, inthat the ice is extremely heavy, hard to handle and the cuts that aremade often produce undersize or oversize slabs. Slabs which are oversizewill not fit into the trays in the food compartment and undersize slabswill not produce the desired refrigeration. An always present danger isthe saw itself, which travels at high speed and could seriously injure aworkman who has become careless after long hours on the job or who hasslipped or fallen into the saw.

SUMMARY OF THE INVENTION The present invention eliminates essentiallyall of the above drawbacks of the system previously used and results inan apparatus which can produce approximately 100 slabsof size 5 by 5 by1 inches per minute.

One of the objects of the present invention is to provide a machine formaking small slabs of dry ice or other material in an extremelyefficient and economical way and with a high capacity.

Another object of the invention is to provide an apparatus which issturdy in structure, reliable, and safe in operation.

Another object is to provide an apparatus which is relatively simple touse and which requires a minimum of manpower to run.

Another object is toprovide an apparatus which is readily adapted to bemoved from location to location to perform its function where needed.

Another object is to provide an apparatus which will produce dry iceslabs consistently of a predetermined size.

Still another object is to provide an apparatus which is designed toessentially eliminate the possibility of jamming.

With these and other objects in view, the invention comprises a cuttingapparatus having a bandsaw and a rotatable table having holders whichperiodically bring blocks of material to be cut across said saw. Meansare provided to insure uniform cuts of preselected thickness.

Other objects and advantages will be apparent from the detaileddescription when considered in conjunction with the accompanyingdrawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a general perspective view ofa cutting machine embodying the invention;

FIG. 2 is an exploded view in perspective showing a rotatable table andsupporting parts thereunder;

FIG. 3 is a developed view, partial in section, of the indexing andcutting arrangements employed in the embodiment shown in FIGS. I and 2;

FIG. 4 is a fragmentary view, partly in perspective and partlydiagrammatical, showing details of anarrangement for holding andreleasing iceblocks upon the rotatable table;

FIG. 5 is a fragmentary view, mainly in perspective, showing anarrangement for sweeping debris from the indexing and cutting portion ofthe device; and 1 FIG. 6 is a diagram used to explain the angularrelationship desired between the line of the sawblade and the trailingedge of an iceblock to be cut.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, thereis shown a rotatable table 20 upon which are mounted a plurality ofbottomless holders or buckets 22. Each holder 22 is mounted over a holein the table, the hole being of the same size and shape as the lowermostperimeter of the holder. Mounted directly below the table 20 is astationary circular sector plate 24 of radius approximately the same asthe radius of the table 20, the sector being illustrated as comprisingapproximately 240 of arc. The uppersurface of the sector plate 24 ispreferably of micarta, or other substance having the property ofpermitting free sliding of iceblocks thereon. The sector plate 24 issubstantially parallel to the table 20 and is spaced below the table bya distance that approximates the least thickness desired for slices tobe cut from iceblocks by the apparatus.

In the space below the table 20 and adjacent to one edge of the sectorplate 24 there is provided an indexing platform 26 and a receiving tray92 occupying together about 60 of arc. The platform and tray aresupported independently of both the table 20 and the sector plate 24,and are adjustable as to height. Supported above the tray 92 with aslight clearance below the bottom surface of the table 20 is a bandsawblade 28 movable in a horizontal plane. The distance from the uppersurface of the platform 26 to the lower level of the kerf of the sawblade 28 can be adjusted to give the desired thickness of slice to becut from the iceblock by the blade 28.

The general mode of operation of the illustrated apparatus is best seenin FIG. 3. An iceblock 98 of proper size to fit easily into the holder22 is put into the holder from above at a time when the holder 22 isdirectly above some portion of the sector plate 24 and the iceblockdrops onto the sector plate 24 and slides on the surface of plate 24 asthe table 20 turns. When the holder 22 is advanced beyond the edge ofsector plate 24, the iceblock falls further to rest upon the uppersurface of the indexing platform 26 as shown by block 100. At a point inthe operation before the block 100 strikes the sawblade 28, means areactuated to clamp the iceblock in the holder 22, the clamping beingeffective upon the portion of the iceblock above the table 20. Theiceblock, clamped against falling, is advanced against the sawblade 28,producing a slice 112 of predetermined thickness which is not supportedafter is leaves the indexing platform 26 and which drops onto thedownwardly sloping tray 92 attached to or integral with the indexingplatform 26 and thence into an output chute 50 along which the sliceslides, for example tosuitable packaging equipment. The upper portion102 of an iceblock from which a slice has been cut continues in clampedposition until the table brings the block again overthe sectorplate 24,when the clamping means may be released, allowingthe block 50 drop tothe sector plate 24 ready for another slicing operation as illustratedby a block 104. It is most important thatthe indexing platform terminatebefore it reaches the area of the sawblade 28. The slice being outshould not be supported from underneath in that this leads to jammingand twisting of the blade. The slice should be free to drop vertically asmall distance at the end of the cut without any hindrance.

The means for clamping and releasing the iceblock in the holder 22 isillustrated in FIG. 4 in the form of two pneumatic rams 30 mounted uponthe table 20 adjacent the respective holder 22. The rarns 30 extendthrough holes 32 in the wall of the holder 22 where they can be pressedagainst the side of the iceblock to effect clamping as needed. The ram30 is doubleacting so that it can be actuated to press against theiceblock or positively moved back to release the pressure and allow theiceblock to fall. Compressed air or other pneumatic medium is brought tothe table 20 from any suitable source, either from a compressor 88within the apparatus shown or from an outside location through a supplytube 34 at the center of rotation of the table 20 and through arotatable coupling 36 into a reservoir 38. From the reservoir 38,distributing tubes 114 run to the individual ram locations. Each ram 30has the usual cylinder 40 and piston with means to admit pneumaticpressure at either end of the cylinder.

The rams 30 operative upon a particular holder 22 are actuated in unisonby admitting compressed air into one end of the cylinder 40 to advancethe ram or into the other end of the cylinder to retract the ram. Theair is directed into either end of the cylinder 40 through a valve 42.The valve 42 is illustrated as a slide valve actuable by means of aspring-loaded slider 44 preferably provided with a roller contactor 46.The spring maintains the valve 42 in the position in which the rams 30are retracted. Adjacent to the circumference of the table 20 there ismounted upon the frame of the machine a cam segment 48 which contactsroller 46 during a part of its rotation. The segment 48 is substantiallycoextensive with the sector plate 24, so that any given pair of rams 30are in the retracted position at all times while the holder 22 to whichthe pair are connected is over the sector plate 24, and the rams arepressed toward the iceblock at all times while the holder 22 is over theopen portion of the sector plate 24.

The chute 50 is preferably straight, with parallel sides 52 spaced apartby a distance approximately equal to the length of a slice, so that theslices are guided in their descent and are prevented from rotating orjamming. The high end of the chute S is located below the sloping tray92 and the direction of the chute is perpendicular to the line of thesaw blade 28. The chute 50 is preferably spring loaded to cushion theshock of the cut slabs falling upon it. The chute is also adjustablymounted so that it can be moved vertically to the desired position.

To clear the indexing platform 26 of broken pieces of ice or otherdebris that may fall there, a sweeper arm 54 (FIG. is pivoted at 84 tothe frame of the indexing table so that it can be moved with said table20. The length of the arm is preferably approximately equal to theradius of the table 20. The end of the arm 54 nearer the circumferenceof the table is pivoted at 86 to the piston rod of a pneumatic ram 56.The ram 56 is similar to the ram 30 but with a longer stroke and isactuated by a slide valve 58 attached to the cam segment 48 in positionto be struck successively by a plurality of earns 60 mounted in anyconvenient manner upon the table 20, for example, one beside each holder22 in such position as to actuate the ram 56 at the instant when theholder 22 ahead of the holder that is actuating the cam has just clearedthe indexing platfonn 26. The flexible tubing 94 allows the ram to beadjusted vertically with respect to the long-way springloaded slidevalve 58.

The pushing stroke of the ram 56 moves the sweeper arm 54 across theindexing platform in the direction toward the chute 50 to sweep thedebris onto the chute. The retracting stroke returns the sweeper arm tothe starting position for the next pushing stroke. It is preferable thatthe pushing stroke be relatively slow to effect good cleaning and theretracting stroke relatively swift. To accomplish this, a restrictedorifice can be inserted in the pneumatic feed line to the end of thecylinder which actuates the pushing stroke. By providing one cam 60 foreach holder 22, the sweeper arm 54 sweeps the indexing platform clearafter each slicing operation of the saw blade 28.

After a cam 60 passes the cam follower 58a, the spring return in theslide valve 58 returns follower 58a to its normal extended position andalso returns the ram 56 to its retracted position.

The saw blade 28 is preferably the blade of a bandsaw, passing aroundtwo supporting wheels 62 and 64 (FIG. 1) mounted in a vertical plane andsupported on the frame of the machine. The bandsaw may be driven by amotor 66 through sprockets 67 and 69, and chain drive 68.

The table 20 is preferably driven by a separate motor 70 supported onthe frame of the machine and connected to the table by a belt 72 uponpulleys 120 and 122, in order that slippage of the belt occurs whennecessary to protect the saw.

The saw motor 66 and the table motor 70 should be interlockedelectrically for the further protection of the sawblade 28 so that thesaw must be running when the table starts rotatmg.

The outer end of the piston rod of the ram 40 which is intended to gripthe iceblock and hold it securely in the holder 22 during the slicingoperation is preferably provided with a micarta disk 74 serrated on theside toward the iceblock.-

Sawblade holders 76 and 78 are provided near each end of the iceblock tobe sliced. The holder 76 is supported on the frame of the machine aheadof the cutting region of the saw, near the center of rotation of thetable 20. This holder is equipped with two sets of rollers. One set 80runs on horizontal axes and presses upon the sawblade 28 above and belowto hold the blade horizontal. The set 82 runs on vertical axes andopposes horizontal deflection of the sawblade 28 under pressure from theiceblock being sliced. The sawblade 28 is driven in the direction fromthe blade holder 76 away from the center of rotation of the table 20toward the holder 78. The holder 78 is preferably made of wood and soshaped as to hold the sawblade in horizontal position and at the sametime resist deflection of the sawblade by the block being cut. The useof wood for the holder 78 tends to avoid accumulation of ice particlescarried to the holder 78 by the sawblade, which particles are likely tofreeze to a metal holder.

The block holder 22 is preferably so oriented upon the table 20 that thetrailing edge of the iceblock leaves the sawblade closely parallel tothe sawblade as shown diagrammatically in FIG. 6. in this way, breakageof the block by the sawblade ending a cut across one comer of the blockis substantially prevented. With the trailing edge so aligned, it isevident that the block will first strike the sawblade at a leadingcorner. Danger of breaking a comer from the block when the blade entersis slight, in fact, a cut is more readily started at a corner than alongan entire side of the block.

For ease of loading, the holder 22 may have three sides instead of four.The narrow side nearer the outer edge of the table 20 may be reduced toa low sill or lip as shown in FIG. 4. The iceblock can be readily slidinto place over the sill 90, which latter will keep the black fromsliding out of the open side of the holder.

The number of holders 22 may be increased or decreaed as desired. In anycase, the arc of the sector plate 24 should be about the proportion ofthe complete circle occupied by two less than the total number ofholders 22, leaving two spaces to accommodate the indexing platform 26,tray 92 and the cutting position. The circumference of the table 20,sector plate 24, and cam segment 48 should be selected of such size asto accommodate satisfactorily the desired number of holders 22.

A machine that has been built and successfully operated is equipped withsix holders for dry ice blocks 10 by 10 by 5 inches. It is mounted upona carriage 96 or wheeled table about 5 feet by 2% feet and about 40inches tall. The rotatable table 20 has a radius of about 20 inches. Thesector plate 24 also has a radius of about 20 inches and a radial widthof about 12 inches.

The motor 66 driving the saw is 1% horsepower, 440 volts. The bandsawhas a li-inch blade passing over pulleys 20 inches in diameter. Themotor 70 for rotating the table 20 is A horsepower, with double beltdrive from a 4 /-inch diameter pulley at the motor to a 16-inch diameterpulley at the table, thereby driving the table at about 8 b revolutionsper minute.

The holders 22 are about 5% by 10% inches inside measurement.

The table 20, sector plate 24, and cam segment 48 are made of steelplate about A inch thick.

The pneumatic tubing is standard A-inch, operated at about 60 pounds persquare inch, although pressures from about 40 to 90 pounds may be used.

The pneumatic cylinders controlling the rams 30 and 56 have diametersabout l rtainch. The rams 30 for the holders have 2 -inch strokes, andthe ram 56 for the sweeper arm 54 has a stroke of inches.

The sweeper arm 54 is a %-inch-square bar about as long as the radius ofthe table 20.

The machine was particularly designed to receive blocks of dry ice 10 by10 by 5 inches in size and to make slices 10 by 5 by 1 inch, or 5 by 5by 1 inch. When slices 5 by 5 by l inch are wanted, the 10 by 10 by 5inch block may be cut into two blocks each 10 by 5 by 5 inches and thesetwo may be placed in the holder 22 side by side, occupying the samespace as the uncut 10 by l0 by 5 inch block. The two rams 30 are sospaced that one ram will grip each half-block, holding the two as ifthey were a single block. The saw then cuts the two blocks in the samemanner as a single block and two 5 by 5 by 1 inch slices fall onto thechute 50 side by side and slide down together.

While illustrative forms of apparatus and methods in accordance with theinvention have been described and shown herein, it will be understoodthat numerous changes may be made without departing from the generalprinciples and scope of the invention.

What is claimed is:

l. A cutting apparatus for cutting portions of predetermined thicknessfrom blocks of material having polygonal cross sections comprising, incombination, a rotatable table, means to rotate said table, a pluralityof block holder means on said table adapted to accept blocks of materialto be cut, each of said block holder means having at least onesubstantially planar surface and a material-locking means for engagingthe block of material to be cut and for rigidly pressing it against thesaid surface in the holder means, bandsaw means having an endless bladewith a straight course positioned adjacent said table, blade holdermeans mounted on said cutting apparatus and positioned to resistdeflection of said endless blade during a cutting operation, indexingmeans to advance the material to be cut from the holder means apredetermined amount so that it may be cut by the straight course of thebandsaw means and to actuate the material-locking means so that thematerial is firmly held in the block holder means against the saidsurface as it is cut by the bandsaw means, the portion of the block cutbeing essentially unsupported so that it is free to drop away from thebandsaw means at the end of the out each block holder means having itssaid at least one planar surface positioned to pass over the straightcourse and oriented on said table so that a comer of a block of materialinitially contacts the straight course thereby facilitating the startingout and so that the trailing edge of the block is substantially parallelto the straight course of the bandsaw blade as the trailing edge passesover said blade.

2. The apparatus defined in claim 1, in which the materiallocking meanscomprises at least one plunger which is adapted to contact the block ofmaterial to be cut.

3. The apparatus defined in claim I, in which the indexing meanscomprises a platform adjustable as to height located adjacent to and ata level below said saw means to receive and support material to be cutas it is advanced from the holder means so that the depth of cut may bedetermined by the height of the platform, and so that thematerial-locking means may be actuated to secure the material to be cutbefore said material contacts the saw means.

4. The apparatus defined in claim 3, together with a sector platelocated below said table and parallel thereto at a height above saidplatform to support an initial advance of the material to be cut beforesaid material is advanced to cutting position by being lowered to saidplatform.

5. The apparatus defined in claim 1, in which the material to be cut issolid carbon dioxide blocks having a rectangular cross section.

1. A cutting apparatus for cutting portions of predetermined thicknessfrom blocks of material having polygonal cross sections comprising, incombination, a rotatable table, means to rotate said table, a pluralityof block holder means on said table adapted to accept blocks of materialto be cut, each of said block holder means having at least onesubstantially planar surface and a material-locking means for engagingthe block of material to be cut and for rigidly pressing it against thesaid surface in the holder means, bandsaw means having an endless bladewith a straight course positioned adjacent said table, blade holdermeans mounted on said cutting apparatus and positioned to resistdeflection of said endless blade during a cutting operation, indexingmeans to advance the material to be cut from the holder means apredetermined amount so that it may be cut by the straight course of thebandsaw means and to actuate the material-locking means so that thematerial is firmly held in the block holder means against the saidsurface as it is cut by the bandsaw means, the portion of the block cutbeing essentially unsupported so that it is free to drop away from thebandsaw means at the end of the cut each block holder means having itssaid at least one planar surface positioned to pass over the straightcourse and oriented on said table so that a corner of a block ofmaterial initially contacts the straight course thereby facilitating thestarting cut and so that the trailing edge of the block is substantiallyparallel to the straight course of the bandsaw blade as the trailingedge passes over said blade.
 2. The apparatus defined in claim 1, inwhich the material-locking means comprises at least one plunger which isadapted to contact the block of material to be cut.
 3. The apparatusdefined in claim 1, in which the indexing means comprises a platformadjustable as to height located adjacent to and at a level below saidsaw means to receive and support material to be cut as it is advancedfrom the holder means so that the depth of cut may be determined by theheight of the platform, and so that the material-locking means may beactuated to secure the material to be cut before said material contactsthe saw means.
 4. The apparatus defined in claim 3, together with asector plate located below said table and parallel thereto at a heightabove said platform to support an initial advance of the material to becut before said material is advanced to cutting position by beinglowered to said platform.
 5. The apparatus defined in claim 1 in whichthe material to be cut is solid carbon dioxide blocks having arectangular cross section.